Float assemblies that support equipment for the surface mixing or aeration of wastewater are well known. For example, typical downflow mixers are shown and described in U.S. Pat. Nos. 4,723,848; 4,422,771; and 2,991,983. In general, such mixers include an annular float that supports the mechanical components of the mixer. The floats support the equipment at the surface of the fluid in a lagoon, basin or other body of water to be treated. A drive motor is mounted on the top of the float and a propeller or other drive shaft is attached to the motor and extends downwardly therefrom below the float and into the fluid through a central opening in the float. A propeller or other fluid mixing device is attached to the drive shaft (see e.g., the OxyMix® pure oxygen mixer and the AquaDDM® direct drive mixer, both products of Aqua-Aerobic Systems, Inc., the assignee of this patent).
The structural arrangement of a typical floating aerator is similar to a floating downflow mixer. The mechanical components of the aerator are supported by a float, which is typically annular. Unlike a downflow mixer, however, an aerator typically pulls the fluid from the basin or lagoon and sprays it above the float to provide aeration (see e.g., the Aqua-Jet® surface mechanical aerator of Aqua-Aerobic Systems, Inc.).
In either case, the float and float assembly (and associated mechanical and electrical equipment and the like) is moored in place in the lagoon, basin or other body of fluid to be treated. Various types of mooring include post mooring, span mooring, cable mooring and pivotal mooring, as will be understood by those of skill in the art. In some situations, the float may be pulled to shore for repair and maintenance. However, in many instances, a plant operator or other maintenance personnel must travel to the float in the location in which it is moored.
In such situations, to effectuate repair or maintenance of the equipment supported by the float assembly on the surface of the fluid, the operator typically takes a boat to the aerator or mixer. The operator attaches the boat to a mooring ring typically provided on the float assembly. The operator then must maneuver onto the top surface of the float assembly, often while carrying tools or other equipment. Clearly, the upper surface of the float assembly may be slippery and the whole float is fairly unstable when loaded on one side with the weight of a person. This presents a potentially dangerous situation for maintenance personnel.
Accordingly, there is a need to provide a safety access system for float assemblies to aid an operator or maintenance person in getting onto and off of the float assembly, as well as helping prevent the operator from falling off of the float while performing repair or maintenance of the equipment. The present inventions are directed to such needs, both for new float assemblies and in retrofitting existing float assemblies.